Characteristic Analysis of the Transition Zone in Carbon Dioxide Miscible Flooding

Abstract

Study on the characteristic of the transition zone in CO2-oil system has important meaning for the research of CO2 miscible flooding. In this paper, one of crude oil samples in Xinjiang oilfield was taken as an example. The minimum miscible pressure (MMP) of CO2-oil system was confirmed through laboratory experiment and numerical simulation separately. And the characteristic of the transition zone was analyzed. The transition zone size and interfacial tension in miscible process were quantified. And their variation tendencies along with the change of the pressure and CO2 injection volume were studied. The results show that it is easier to reach miscible state in higher pressure and CO2 injection volume. This work provides a reference for the further research of CO2 miscible flooding.